1. Field of the Invention
The present invention relates to an infrared touch screen device. More particularly, the present invention relates to an infrared touch screen device capable of smoothly sensing the contact positions of a plurality of touch points and sensing multi-touch points when a plurality of touch points are produced.
2. Description of the Related Art
Generally, a touch screen device perceives the positions of characters and specific icons displayed on a picture by contacting them with objects such as man's hands or pen, or the like, without using an input device such as a mouse, and calculates input signal and performs a specific function.
This touch screen device is classified as a resistance film way, a capacitance way, an ultrasound way and a infrared way, depending on a way of calculating the position to be contacted on a screen wherein the resistance film way and the capacitance way have been mainly used.
Among the position calculating ways, the infrared way will be described hereinafter.
FIG. 1 is a perspective view showing a configuration of an infrared touch screen device according to the related art.
As shown in FIG. 1, a first and second light emitting portions 13, 14 provided on one of upper side and bottom side and on one of left side and right side, respectively, of an infrared way-touch panel are arranged in the infrared way-touch panel to which an infrared way is applied wherein the first and second light emitting portions including a plurality of infrared emitting elements 12 for lighting laser (infrared) along an outline of a screen 10.
Furthermore, a first and second light receiving portions 17, 18 including a plurality of light receiving elements 16 are arranged, respectively, on one of left and right sides and on one of upper and bottom side of the outline of the screen 10 where the first and second light emitting portions 17, 18 are not provided.
As a result, the laser beams pass as a matrix form between the first and second light emitting portions 13, 14 and the first and second light receiving portions 17, 18 on the screen 10. Accordingly, when a user' finger or a pen, or the like contacts a specific portion on the screen 10, the light in contact with the finger or the pen, or the like is to be blocked.
As a result, the light is not incident to the first and second light receiving portions 17, 18 at the contacted position on the screen 10.
The touch screen device recognizes the contacted position by sensing the position from which the light is not incident to the first and second light receiving portions 17, 18 and transfers the sensed information to X/Y decoder 19.
However, according to the prior infrared way, even though a plurality of infrared lighting elements and light receiving elements are used, there is a limitation to detecting simultaneously a plurality of touch points.
Further, the screen may be damaged by touching it with a finger or a pen, or the like.
In addition, since a resolution ability with respect to the contacted position on the screen is determined depending on the numbers of the infrared lighting elements and the light receiving elements, the numbers of the light emitting elements and the light receiving elements have to be increased in order to improve the resolution ability, and thereby increasing a production cost of the screen.
Therefore, a need exists for a system and method for performing a self diagnosis of a device without the inconvenience caused when manually selecting a self diagnosis item from a computer or a user interface.